It is imperative to root your Galaxy S3 I9305 before installing third-party root-based apps or custom ROMs on it. IBTimes UK brings you a step-by-step guide to rooting the device using CF-Auto-Root with ODIN.

Key Points to Note

Rooting your device may erase personal data and settings on it. Hence, it is advisable to back up apps, important data and settings before you proceed.

Warranty on the device will be void after rooting it. Just reinstall the official firmware update to reclaim the hardware warranty.

The instructions provided in this guide are meant for reference purpose only and do not cover any warranty claims with device damage or issues arising out of rooting the official Android 4.1.2 Jelly Bean firmware on Galaxy S3 I9305. Users are advised to proceed at their own risk.

Pre-requisites

Verify that your phone has at least 80 percent battery power before you proceed, to prevent unexpected device shutdown (due to battery drain) while flashing the CF-Auto-Root tool using ODIN on your Galaxy S3 I9305

Ensure that the correct USB drivers are installed for your Galaxy S3 on the computer (download USB drivers)

Make sure that your Galaxy S3 phone is running on the official Android 4.1.2 XXBLL3 Jelly Bean firmware before you begin the rooting process

4. Boot the Galaxy S3 I9305 in Download Mode by pressing and holding Volume Down and Home buttons together while tapping the Power button. A Warning message will appear on screen, now hit Power button again to progress into Download Mode.

5. Launch Odin3 v1.85.exe (check Step 2) as an Administrator, as Admin privileges is required to complete the process successfully.

6. Connect your Galaxy S3 to the computer with original USB cable. A message reading "Added!!" will appear in Odin's message box at the bottom left. If you fail to get this message, then retry the process with another USB port (preferably the rear USB port on your computer). If all else fails then just reinstall the USB drivers for the phone. When you get "Added!!" message in Odin, you can proceed to the next step. You will now see the ID: COM port with a number in Yellow, indicating successful connection of your device with computer.

7. Choose following files in Odin using respective command buttons:

Click the PDA button, and choose the CF-Auto-Root-m3-m3zh-gti9305.tar.md5 file.

9. Verify that the previous steps - step 7 and step 8 - are done correctly. Then hit the START button to begin the flashing process.

10. Once the ROM is flashed, you will get a PASS message with green background in the left-most box at the very top of Odin. The phone will now automatically reboot and Samsung logo will appear on screen. Now, just disconnect the device's USB cable from computer.